Shear pucks are employed in construction for connecting abutting columns or beams to each other. The pucks are made of either metal or composite materials such as fiber-glass, and are usually in the form of cylindrical sections.
Composite material shear pucks are used extensively, for example, in the construction of cooling towers, which are employed by power plants or other industrial facilities to cool and recycle cooling water that is heated by the industrial process. Cooling towers are usually square or rectangular in shape and can typically range in size from 150' to 50' on a side to from 20' to 50' in height. The water to be cooled is pumped up to the top of the tower then allowed to flow downward to the bottom of the tower. Exhaust fans at the top of the tower are operated to suck the vapor created by the cooling of the water up and out through the open top of the tower.
The inside of the cooling tower is comprised of a matrix of wooden vertical columns connected to horizontally disposed beams. The vertical columns can be typically four inch by four inch wooden beams with a length about the height of the tower. The horizontal beams can be, typically, two inches by six inches in dimension. The vertical columns are usually set about six feet apart and the horizontal beams are arranged in levels about every six feet. Thus, in a tower which is thirty six feet high, there are six levels. The average cooling tower therefore requires many thousands of connections between the vertical columns and the horizontal beams.
Depending on the load carried on the beam, the connection between a beam and a column may be a bolt only, or a combination of shear pucks and a bolt. The purpose of the shear puck is to spread the load carried by the beam to a larger area than carried with a bolt only, i.e. the circumferential surface area of the shear puck rather than the much smaller circumferential surface area of the bolt. When the cooling tower is designed, the design engineer determines the load distribution on the beams and then determines the number and placement of bolt only connections and shear puck with bolt connections. Also, depending on the specific loads borne at each location, the size of the shear pucks to be use is determined.
Present shear pucks of composite material, such as fiber-glass, are made by a high temperature compression molding manufacturing process. The process requires the use of metallic mold increasing the costs of the pucks. In addition, due to curing problems, the inner area of the pucks must be hollowed out, thereby weakening the strength of the puck and decreasing its load bearing capability. There is, therefore a need for a shear puck which is easier, faster and more economical to manufacture and which has greater strength and load carrying capacity than presently available shear pucks.